Ce-TiO_2粉体的结构与性能研究

Study on the Structure and Performance of Ce-TiO_2 Powder

为了研究离子添加对TiO2粉体结构与性能的影响,采用Sol-gel法制备了Ce-TiO2粉体,在不同Ce4+浓度条件下,使用XRD、XPS、PL等仪器表征了样品的晶相、杂质能级、晶粒尺寸、电子-空穴对复合率等微观结构,并与光谱响应曲线、降解率等宏观性能相联系,阐述了微观结构与宏观性能的定量对应关系。结果表明:随着Ce4+浓度的增加,样品结晶被阻碍,能带间出现新能级且变强,晶粒尺寸先变小后变大,晶格缺陷增多导致电子-空穴对复合率存在极小值。晶相与杂质能级影响了光谱响应曲线,微观结构综合作用影响了Ce-TiO2对亚甲基蓝的降解率。研究结果为定量研究改性TiO2提供了实验依据。

In order to investigate the influences of addition on the micro-structure and macro perforrnance of TiO2 powders, the Ce-TiO2 compounds with different Ce4＋ concentrations were prepared by sol-gel method. The crys- tal phase, impurity energy levels, grain size, and hole-electron recombination rate of Ce-TiO2 were characterized by XRD, XPS, and PL measurements. These observations were combined with the macro-performance, such as light re- sponse curve, photocatalytic degradation rate, and discussed the relationship between micro-structure and macro-per- formance. The results suggest that with the increasing of Ce4＋ concentration, the phase transition is prevented, the impurity energy levels are formed and strengthened, the grain size firstly decreases and then increases, and the in- crease of lattice defects leads to the exist of minimum of hole-electron recombination rate. Therefore, the crystal phase and impurity energy levels impact the light response curve, and the combination effects of micro-structure determine the photocatalytic degradation rate of Ce-TiOe powders for methylene blue. The results provide experimental basis for further TiO2 modification study.